EPIC Observations of Anomalous X-ray Pulsars

GT HD49798 is a sdO6 star in a spectroscopic binary with orbital period 1.55days. In Xrays it has a very soft spectrum and a periodicity at 13 s,indicating that the companion is a magnetized compact object. The proposedobservation will allow to measure the period evolution (and thus distinguishbetween a ns and a wd) and to confirm the NIV absorption edge suggested by ROSATresults. NOTE FOR THE PLANNING: 3 pointings of 5 ksec each are required, in order tocover different phases of the 1.55 day orbit. The choice in the time constraintsform (repeat every 11 hours) is just a possibility: such a tight constraint on the spacing is not required, as far as different phases are sampled. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]